A miR-124/ITGA3 axis contributes to colorectal cancer metastasis by regulating anoikis susceptibility.

Metastasis is the major cause for the death of patients with colorectal cancer (CRC). Anoikis resistance enhances the survival of cancer cells during systemic circulation, thereby facilitating secondary tumor formation in distant organs. miR-124 is a pleiotropically tumor suppressive small non-coding molecule. However, its role and mechanism in the regulation of cancer cell anoikis are still unknown. Here, we found that overexpression of miR-124 promotes anoikis of CRC cells in vitro and in vivo. In silico analysis and the experimental evidence supported that ITGA3 is a bona fide target of miR-124. Moreover, we identifies that ITGA3 plays a critical role in the regulation of anoikis sensitivity in CRC cells. Finally, our analysis in TCGA datasets demonstrates that high levels of ITGA3 are closely associated with poor prognosis in CRC patients. Collectively, we establish a functional link between miR-124 and anoikis susceptibility and provide that a miR-124/ITGA3 axis could be a potential target for the treatment of metastatic CRC.

The adenovirus-mediated transfer of PTEN inhibits the growth of esophageal cancer cells in vitro and in vivo.

The development and progression of esophageal cancer is associated with multiple alterations in the genome, including loss of the tumor suppressor phosphatase and tensin homolog deleted from the chromosome 10 (PTEN) gene. The purpose of this study was to determine the effects of adenovirus-mediated MMAC/PTEN expression on the growth and survival of human esophageal cancer cells in vitro and in vivo. We found that compared to control cells, overexpression of PTEN significantly suppressed growth and induced apoptosis in esophageal cancer cell lines Eca-109 and TE-1 via downregulation of Bcl-2 expression and changes in cell-cycle progression. Adenovirus PTEN also inhibited the growth of subcutaneous tumor xenografts by significantly reducing tumor size in vivo. Thus our results confirm the proposed functional role of MMAC/PTEN as a regulator of esophageal cancer progression in vivo and in vitro. PTEN might be an important biological marker and potential therapeutic target in the treatment of human esophageal cancer.

Enhancement of radiosensitivity by roscovitine pretreatment in human non-small cell lung cancer A549 cells.

Roscovitine has been reported to have anti-proliferative properties and is in process of undergoing clinical trials. In addition to its intrinsic anticancer properties, it has recently been suggested that roscovitine may also enhance the activity of traditional chemo- and radio- therapies in certain cancer cell lines. The purpose of this study was to define the activity of roscovitine in increasing radiosensitivity of human non-small cell lung cancer (NSCLC) cell line A549 cells in vitro. A549 cells were exposed to ionizing radiation (IR) of gamma-ray with or without roscovitine pretreatment. Clonogenic assay was performed and cell cycle and apoptosis were analyzed by flow cytometry. Expression of PARP, Ku70 and Ku80 proteins was detected by Western blot. The active form of caspase-3 positive cells were measured by flow cytometry. Our results showed that roscovitine caused dose-dependent apoptosis in A549 cells. Pretreatment with minimally toxic concentration of roscovitine significantly radiosensitized A549 cells by inhibiting colony formation. We then examined potential mechanisms that may contribute to the enhanced radiation response induced by roscovitine. Our results showed that the combination treatment significantly induced apoptosis in A549 cells compared to roscovitine or IR treatment alone. Meanwhile, in the co-treatment group, the percentage of cells with the active form of caspase-3 was markedly increased, while roscovitine or IR alone had little effect. Roscovitine decreased S phase cells when used alone or in sequential combination with IR. Furthermore, this combination treatment blocked DNA repair process after IR, indicated by down regulation of Ku70 and Ku80 proteins, while the singly used treatment did not. Taken together, these results suggest that roscovitine has the potential to act as a radio-sensitizer in A549 cells by promoting caspase-3 activity and increasing apoptosis, affecting cell cycle distribution and impairing DNA repair process.

Synthesis of ribozyme against vascular endothelial growth factor165 and its biological activity in vitro.

AIM: To investigate the designation, synthesis and biological activity of against vascular endothelial growth factor165 (VEGF165) ribozyme. METHODS: The ribozyme against VEGF165 was designed with computer. The transcriptional vector was constructed which included the anti-VEGF165 ribozyme and 5', 3' self-splicing ribozymes. The hammerhead ribozyme and substrate VEGF165 mRNA were synthesized through transcription in vitro. The cleavage activity of the ribozyme on target RNA was observed in a cell-free system. RESULTS: The anti-VEGF165 ribozyme was released properly from the transcription of pGEMRz212 cleaved by 5' and 3' self-splicing ribozymes which retained its catalytic activity, and the cleavage efficiency of ribozyme reached 90.7%. CONCLUSION: The anti-VEGF165 ribozyme designed with computer can cleave VEGF165 mRNA effectively.

VEGF165 antisense RNA suppresses oncogenic properties of human esophageal squamous cell carcinoma.

AIM: To investigate the effect of antisense RNA to vascular endothelial growth factor165 (VEGF165) on human esophageal squamous cell carcinoma cell line EC109 and the feasibility of gene therapy for esophageal carcinoma. METHODS: By using subclone technique, the full length of VEGF165 amino acid cDNA, which was cut from pGEM-3Zf+,was cloned inversely into the eukaryotic expression vector pCEP4. The recombinant plasmid pCEP-AVEGF165 was transfected into EC109 cell with lipofectamine. After a stable transfection, dot blot, enzyme-linked immunosorbent assay (ELISA),laser confocal imaging system analysis, transmission electron microscopy and flow cytometry were performed to determine the biological characteristics of EC109 cell line before and after transfection in vitro and whether there was a reversion in the tumorigenic properties of the EC109 cell in vitro. RESULTS: The eukaryotic expression vector pCEP-AVEGF165 was successfully constructed and transfected into EC109 cells. The expression of VEGF165 was significantly decreased in the transfected cells while the biological characteristics of the cells were not influenced by the expression of antisense gene. The tumorigenic and angiogenic capabilities were greatly reduced in nude mice, as demonstrated by reduced tumor end volume (820+/-112.5)mm(3) vs (7930+/-1035)mm(3) and (7850+/-950)mm(3), P<0.01) and microvessel density (average number: (8.5+/-1.2)mm(-2) vs (44.3+/-9.4)mm(-2) and (46.4+/-12.6)mm(-2), P<0.01) in comparison between experimental groups empty vector transfected group and control group. CONCLUSION: The angiogenesis and tumorigenicity of human esophageal squamous cell carcinoma were effectively inhibited by VEGF165 antisense RNA. Antisense RNA to VEGF165 can potentially be used as an adjuvant therapy for solid tumors.

[Clinical observation on intractable hiccup treated by acupuncture at the lower he-sea points mainly].

OBJECTIVE: To verify the clinical efficacy on intractable hiccup treated by acupuncture at the lower He-sea points mainly. METHODS: Fifty-two cases were randomized into an acupuncture-moxibustion group and a western medication group, 26 cases in each one. In the acupuncture-moxibustion group, acupuncture was applied to Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39). The mild moxibustion was applied to Zhongwan (CV 12) and Xiawan (CV 10). In the western medication group, the intravenous drop with lidocaine was administered. The efficacy and the score changes of the main associated symptoms were compared in the two groups. RESULTS: The total effective rate was 96.1% (25/26) in the acupuncture-moxibustion group, which was better than 69.3% (18/26) in the western medication group (P.<0.01). After treatment, for the patients in both groups, the scores of the main associated symptoms such as anxiety, tension, insomnia, respiratory symptoms and the restlessness in conversation were all improved (all P<0.05). The improvements in the acupuncture-moxibustion group were much obvious than those in the western medication group (all P<0.05). CONCLUSION: Acupuncture at the lower He-sea points mainly relieves effectively the symptoms of hiccup and the efficacy is better than that with lidocaine.

Protective effect of magnolol on lipopolysaccharide-induced acute lung injury in mice.

Magnolol, a tradition Chinese herb, displays an array of activities including antifungal, antibacterial, and antioxidant effects. To investigate the protective effect of magnolol on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. ALI was induced in mice by intratracheal instillation of LPS (1 mg/kg). The mice received intratracheal instillation of magnolol (5 µg/kg) 30 min before LPS administration. Pulmonary histological changes were evaluated by hematoxylin-eosin stain and lung wet/dry weight ratios were observed. Concentrations of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, and myeloperoxidase (MPO) activity were measured by enzyme-linked immunosorbent assay. Expression of cyclooxygenase (COX)-2 in lung tissues was determined by Western blot analysis. Magnolol pretreatment significantly attenuated the severity of lung injury and inhibited the production of TNF-α and IL-1ß in mice with ALI. After LPS administration, the lung wet/dry weight ratios, as an index of lung edema, and MPO activity were also markedly reduced by magnolol pretreatment. The expression of COX-2 was significantly suppressed by magnolol pretreatment. Magnolol potently protected against LPS-induced ALI and the protective effects of magnolol may attribute partly to the suppression of COX-2 expression.

[Effect of inhabitation of VEGF expression with RNA interference on lung cancer therapy].

AIM: To observe the effect of inhabitation of VEGF expression by RNA interference on the therapy of lung cancer and to obtain a novel strategy of lung cancer therapy by RNA interference. METHODS: A segment of VEGF-siRNA was synthesized according to the code of siRNA design. The constructed pSilencer-3.1-VEGF vectors were stably transfected into A549 cell line. Then the expression of VEGF was detected in stable transfectant A549 cell line by TR-PCR and Western blot. Meanwhile, the growth of stable transfectant A549 cell line and the angiogenesis of endothelial cells were studied. The tumor volume was detected in stable transfectant A549 bearing mice. RESULTS: The expression of VEGF in stable transfectant A549 cell line was obviously inhibited by pSilencer-3.1-VEGF-2. Although it did not inhibit the growth of A549, it decreased the angiogenesis of endothelial cells. In vivo, compared with control group, the tumor in the pSilencer-3.1-VEGF-2-A549 bearing mice(P<0.05)growth was obviously at a slow, and the survival obviously lengthened in the pSilencer-3.1-VEGF-2-A549 bearing mice(P<0.05). CONCLUSION: A pSilencer-3.1-VEGF vector has been successfully constructed. pSilencer-3.1-VEGF-2 can silence the expression of VEGF in A549. It can inhibit the angiogenesis of endothelial cells in vitro and the tumor growth and lengthen the survival of the bearing mice in vivo.

Wortmannin potentiates roscovitine-induced growth inhibition in human solid tumor cells by repressing PI3K/Akt pathway.

Roscovitine has been reported to have anti-tumor effects in some cancer cell lines. The phosphatidylinositol-3-kinase (PI3K) signaling, which activates protein kinase B (PKB)/Akt, is known to mediate cell survival. The current study examined the role of wortmannin, a PI3K inhibitor, as a chemosensitizer for roscovitine and its proposed mechanism of action. The results showed that wortmannin significantly chemosensitized three human tumor cell lines (A549, HCT116 and HeLa cells). In A549 cells, wortmannin increased roscovitine-induced apoptosis in a dose-dependent manner, which was correlated with the inhibition of phosphorylated PKB/Akt level. Wortmannin enhanced the effects of roscovitine by causing pronounced reduction of mitochondrial transmembrane potential (MMP) and increases of cytochrome c release and active caspase-3, as well as enhanced activation of Bax and Bad, including Bax oligomerization and mitochondrial translocation of Bax and Bad. Taken together, these results provide evidence for the potential application of roscovitine/wormannin combination in clinical treatment for solid tumors.

[Experimental study on the effect of VEGF165 antisense RNA on human squamous cell carcinoma of esophagus].

AIM: To investigate the effect of antisense RNA against vascular endothelial growth factor 165 (VEGF165) on human esophagus squamous cell carcinoma cell line EC109. METHODS: Eukaryotic expression vector for VEGF165 antisense RNA was constructed and identified. Recombinant plasmid was transfected into EC109 cells and the transfected EC109 cells were inoculated subcutaneously to nude mice. The biological characteristics and tumorigenicity of transfected EC109 cells were observed by in situ hybridization, laser confocal microscope, transmission electron microscopy and flow cytometry. RESULTS: The eukaryotic expression vector pCEP-AVEGF165 was successfully constructed and expressed in transfected EC109 cells. The rate of VEGF165 expression dropped by 75% in transfected cells. The morphology and cell cycle of transfected EC109 cells were not affected by the antisense RNA, but the tumorigenicity and angiogenesis of transfected EC109 cells were greatly reduced in nude mice. The volume of tumors in pCEP-AVEGF165 transfected group, empty vector transfected group and control group were (820+/-112.5) mm3, (7 930+/-1 035) mm3 and (7 850+/-950) mm3, respectively. The microvessel density of the three groups were (8.5+/-1.2)/mm2, (44.3+/-9.4)/mm2 and (46.4+/-12.6)/mm2, respectively. CONCLUSION: The angiogenesis and tumorigenicity of human esophageal squamous cell carcinoma were effectively inhibited by VEGF165 antisense RNA, which may be applied to treat solid tumor in the future.